The next "station", if you can call it a station, will be Castlebar Park which was a nice place until 1935. Now, only leave the train here if you wish to use the "shelter" to pee in. Everyone else seems to.
New Cross, New Cross Gate and Shoreditch had one platform when they were part of the Underground. Embankment and Wood Lane (Central line) did when first built. King William Street did as well, but I can't remember whether that was rebuilt from one to two or vice versa.
The essential things in life are seen not with the eyes, but with the heart. --Antoine de St. Exupery
I think King William Street started with a central track with two outer platforms (like Tower Gateway) and then was changed to be a central platform with a track either side. Stratford DLR also started as a single platform.
Apologies I should have merged this with my previous post.
For clarity, does "single platform station" mean a station with only one platform with a single track next to it or does it also include stations with a platform having tracks on two sides? Heathrow 4 and Kensington/Olympia would count as the first.
(Some rail systems use "platform" to be the passenger area adjoining one or more tracks, so "Platform 1" could have A and B sides.)